1. Field of the Invention
The present invention relates generally to improvements in the field of fiber optics, and particularly to advantageous aspects of systems and methods for reducing splice loss in optical fibers.
2. Description of Prior Art
Splice loss is a significant issue in the design and implementation of optical fiber systems. For example, when a standard single-mode fiber (SMF) is spliced to a dispersion compensating fiber (DCF), also known as an inverse dispersion fiber (IDF), it is not uncommon for splice losses greater than 0.1 dB to result, as well as wavelength-dependent splice loss of greater than 0.1 dB per 100 nm. These splice losses typically limit the performance of dispersion-managed fiber spans and dispersion compensating modules (DCMs).
Thus, there is an ongoing effort to develop techniques and systems for reducing splice loss. Certain types of post-splice heat treatments have been described for reducing splice loss, predicated on diffusion of the dopants in the fiber. See, for example, Krause, John T. et al., “Splice Loss of Single-Mode Fiber as Related to Fusion Time, Temperature, and Index Profile Alteration,” Journal of Lightwave Technology, Vol. LT-4, No. 7, 1986, pp. 837-40; Tam, H. Y., “Simple Fusion Splicing Technique for Reducing Splicing Loss between Standard Singlemode Fibres and Erbium-Doped Fibre,” Electronics Letters, Vol. 27, No. 17, 1991, pp. 1597-99; and Ando, Yasuhiro, “Low-Loss Optical Connector between Dissimilar Single-Mode Fibers Using Local Core Expansion Technique by Thermal Diffusion,” IEEE Photonics Technology Letters, Vol. 4, No. 8, 1992, pp. 1028-31.
Another described process relies upon stretching an optical fiber in the vicinity of a splice. Mortimore, David B. et al., “Technique for Reducing Fibre Joint Loss,” U.S. Pat. No. 4,900,114, Feb. 13, 1990. A variation of this technique relies upon compressing an optical fiber in the vicinity of a splice. O'Brien, E. M. et al., “Low-Loss Fattened Fusion Splices between Different Fibers,” Electronics Letters, Vol. 35, No. 2, pp. 168-69, 1999.